The present invention is directed to a novel golf club assembly system including a novel method and novel structure for facilitating assembly of a golf club head to a golf club shaft.
The prior art presents numerous methods for assembling golf clubs. However, most of these methods are directed to assembly in a factory by a manufacturer of golf clubs, for sale in the assembled condition. Today golf clubs are available with a wide variety of club head configurations, as well As with varying shaft designs and stiffness. As such, it will be seen that providing every possible combination thereof requires the production and maintenance of a very large inventory or supply of golf clubs to meet all possible customer needs.
Such golf clubs are custom assembled to customer specifications. However, this involves a considerable length of time in processing orders to the factory, as well as considerable expense in factory operation on such a custom basis. Alternatively, many pro shops, sporting goods stores, retail stores and the like provide such custom assembly service utilizing a stock or inventory of individual shafts and heads of different kinds and types, and assembling selected heads and shafts to customer specifications. This greatly reduces the amount of inventory necessary as well as making custom assembly available on a relatively convenient and less expensive basis. However, most such sporting good stores and pro shops are not equipped with special assembly machinery and equipment required, and often do not employ skilled assembly personnel. Moreover, the purchase of such specialized equipment and employment of such specially trained personnel greatly increases the cost of such customized assembly service.
The prior art has devised a number of simplified assembly methods, primarily involving assembly of a shaft with a hosel portion of a club head utilizing only a bonding agent such as an epoxy resin, or the like. That is, the shaft end which is dimensioned to slideably interfit within the club head hosel is coated with a quantity of a selected adhesive or bonding agent and the parts are then interfitted permitting the bonding agent to cure and effect a bond therebetween. However, as previously mentioned, most such pro shops or retail sporting good shops are without specialized personnel or equipment for carrying out this operation. Hence, they are fearful that the bond thus effected may for some unforeseen reason fail in service, causing inconvenience as well as possible injury. Such separation of head and shaft after assembly would be damaging to the reputation of the shop, and might also subject the shop to personal injury claims.
Accordingly, it is desirable to provide a reliable, and preferably mechanical means of effecting club head-to-shaft assembly, still without requiring specialized tools or equipment, or specialized training on the part of the assembler.
The prior art envisions a number of arrangements for mechanical assembly of golf club head and shaft's; however, most of these have involved relatively complex and difficult to manufacture pieces, sub-assemblies, and the like, or require a relatively complex and difficult process of assembly. Additionally, the prior art also discloses a number of interchangeable shaft and club head assemblies. However, by their nature, these assemblies are readily disassemblable or interchangeable, and thus, they lack the degree of permanence and rigidity desired of custom assembled golf clubs, to which the present invention is directed.
Some of these prior art assembly arrangements utilize a threaded engagement of the shaft with the hosel. However, such engagement provides no means to limit relative rotation between shaft and head. This design does not permit preassembly of the shaft with a grip bearing indicia for alignment with a predetermined portion of the club head, as is desired in many golf club designs. That is, since the threaded engagement provides no predetermined stop or fully advanced position with respect to relative rotation, it is not possible to attain proper alignment of the indicia on the preassembled grip with the club head when utilizing threaded engagement with the shaft. Moreover a threaded connection permits rotation of the head relative to the shaft when the ball is struck. In addition to resulting in ineffective striking of the ball and unsuitable performance the threaded type of connection also permits further advancement of the shaft into the hosel portion of the head. Such further advancement may cause undue stress forces to build within the hosel, ultimately resulting in failure or splitting of the hosel or club head, this problem is especially acute where wood type club heads are involved.